Add leak test

Author: iluuu1994

Zend/tests/gh10168_3.phpt

@@ -8,7 +8,7 @@ class Test
 
 	public function __construct() {
 		if (self::$a === null) {
-			var_dump(self::$a = $this);
+			var_dump(self::$a = &$this);
 		} else {
 			var_dump(self::$a = $this);
 		}

Zend/tests/gh10168_5.phpt

@@ -0,0 +1,32 @@
+--TEST--
+GH-10168 (heap-buffer-overflow at zval_undefined_cv): assign typed prop
+--FILE--
+<?php
+
+class Foo {}
+
+class Test
+{
+	static Test|Foo|null $a = null;
+
+	public function __construct() {
+		var_dump(self::$a = $this);
+	}
+
+	function __destruct() {
+		var_dump(self::$a = new Foo());
+	}
+}
+new Test();
+new Test();
+
+?>
+--EXPECT--
+object(Test)#1 (0) {
+}
+object(Foo)#3 (0) {
+}
+object(Test)#2 (0) {
+}
+object(Foo)#1 (0) {
+}